Operating and ignition device for an explosion-driven ramming hammer



March 20, 1956 A. N. WAMPACH 2,738,777 OPERATING AND IGNITION DEVICE FORAN EXPLOSION-DRIVEN RAMMING HAMMER Filed Feb. 7, 1951 INVENTOR. 09 6:Mac/ Mam mo mu g 6. sm'lfm,

United States Patent OPERATING IGNITION DEVICE FOR AN EXPLOSION-DRIVENRAMMING HAMMER Aloyse Nicolas Wampach, Luxembourg, LuxembourgApplication February 7, 1951, Serial No. 209,339

Claims priority, application Luxembourg February 15, 1950 7 Claims. (Cl.123--7) This invention relates to portable explosion-driven ramminghammers and more particularly to a novel operating system therefordevice for portable explosion-driven ramming hammers.

One of the objects of the'present invention is to provide a ramminghammer which may be manually actuated in a simple convenient manner forstarting the ramming operation of the ramming hammer.

Another object of the present invention is to provide a ramming hammerwith a structure which permits exhaust gases to flow from the combustionchamber after the piston of the ramming hammermoves past a predeterminedpoint irrespective of the position which the piston takes after itpasses this predetermined point.

Also, it is an object of the presentinvention to provide a ramminghammer capable of accomplishing the above objects and at the same timemade up of simple, ruggedly constructed elements which are very reliablein operation.

With the above objects in view, the present invention mainly consists ofa ramming apparatus which includes a cylinder having a top wall andbeing formed in a side wall portion with an exhaust port located distantfrom the top wall. A piston is slidably mounted in the cylinder formovement above and below this exhaust port, and this piston has a topface forming a combustion chamber with the top wall of the cylinder. Afirst spring means is operatively connected to said piston for urgingthe same toward said top wall. An exhaust valve means is mounted on saidpiston to provide communication between the interior parts of saidcylinder located on opposite sides of said piston. The said exhaustvalve means include a valve member which engages said top face of saidpiston in the closed position of said exhaust valve means and is spacedfrom said top face of said piston and located in said combustion chamberin the open position of said exhaust valve means. A second spring meansis operatively connected to said valve member for urging the same to theopen position thereof. An intake valve means communicates with saidcombustion chamber for admitting a combustible mixture thereto duringmovement of said piston away to said top wall, and means for manuallymoving said piston away from said top wall of said cylinder to draw acombustible mixture into said combustion chamber and for simultaneouslymanually moving said valve member to the closed position thereof,whereby, when the mixture in said combustion mixture is ignited, thepressure of the explosion will maintain said valve member in the closedposition thereof, and whereby, after said exhaust port is locatedbetween said piston and top wall, the pressure of the explosion will bereduced, said first spring means will move said piston toward said topwall, and second spring means will move said valve member to the openposition thereof to provide communication between said combustionchamber and exhaust port when said piston is located between saidexhaust port and top wall of said cylinder.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

Referring now to the drawing, the portable explosiondriven ramminghammer devised according to the present invention includes, two springs2 housed within the hollow arms 6 of a U-shaped actuating member 20which is fixedly positioned around the top end of cylinder 1. As shownin the drawing, only half of U-shaped member 20 is visible, the otherhalf being broken away so as not to unduly encumber the drawing. Springs2 are secured to the lower ends of the arms 6 of the U-shaped member 20in any suitable way and are suspended from the hooks 4 which extendoutwardly from the top wall 26 of cylinder 1.

The portions of arms 6 which are disposed adjacent to the side walls ofcylinder 1 are longitudinally slotted permitting the said actuatingmember 20 to be slidably moved vertically with respect to hooks 4 whichrespectively extend freely through the slots of arms 6.

Horizontally disposed handles 8, extending outwardly from and fixed toarms 6 of actuating member 20, provide a means whereby member 20 isreadily gripped by hand and thereafter depressed to actuate the ramminghammer. As may be seen in the drawing, a rod 19 is rigidly affixed atits top end to actuating member 20 centrally of the latter, said rod 19extending axially into cylinder 1 slidably through top wall 26 thereof.As U-shaped member 20 is depressed by the operator, rod 19 willnecessarily move downwardly within cylinder 1.

Advantages resulting from this construction are that the springs 2 maybe of great length and are particularly easy to mount because it is onlynecessary to attach the top ends of the said springs to hooks 4 and toattach their bottom ends to the lower ends of arms 6 in any suitableway.

The device provides a further advantage in that the air expelled fromthe upper chamber 27 by the upward stroke of the piston 17 and the aircontained therein during the downward stroke will be usefully employedin cooling the operating cylinder. Such an arrangement was impracticableheretofore because the two springs necessarily had to pass through thetop wall of the cylinder.

An ignition magneto (not shown) is mounted upon the top wall 26 of thedevice for producing the spark to initiate combustion.

Conventional portable explosion-driven ramming hammers are provided withan auxiliary piston which expels the burnt combustion gases and at thesame time sucks in the fresh combustion mixture. Such ramming-hammersaccordingly require two pistons, namely an operating piston connectedwith the ramming-bar and a drive piston for sucking in the gas mixtureand discharging the burnt gases.

The present invention comprises a ramming hammer in which all thenecessary operations are obtained by a single piston, all need for anauxiliary piston being eliminated.

As shown in the drawing, the piston 17 is separated from both strikerbar 18 and rod 19 connected the U- shaped member 20. The striker bar 18is provided at its top with a spring-seating flange 21 against which thespring 22 for retracting the ram 23 is seated. The retracting stroke ofthe piston 17 is produced by a spring 24 housed in a bore 25 in thestriker-bar 18. Spring 24 is of suflicient length to drive the piston 17upwards until it abuts against top wall 26 thereby insuring that all theresidual gases'ofcombustion'are discharged 'from the combustion chamber27.

The intake stroke commences with piston 17 by reason of the downwardmovement-of U-shaped member 20 and rod '19, advancing until it abutsagainst the flange 21 and it is at this time that the gaseous mixture,introduced within the combustion chamber during downward movementof thepiston, is ignited. As the piston 17 is moved downwardly the combustionmixture is sucked in through the intake valve 28 and duct 28a into thecombustion chamber 27 through the tube 29.

An exhaust valve 30 is provided to permit combustion gases'topassthroug'h piston 17,'the said valve being'urged to itsopenposition bya spring 31 andbeing closed when pressed against its seating as soon asthe piston abuts against top wall 26. This valve is held in closedposition by the rod 19 throughout the intake stroke and untilignitionoccurs. Thereafter the explosion pressure retains the valve 30upon'its seat. When the piston 17 clears exhaust aperture 32, thepressure upon valve 30 is diminished thereby permitting spring 31 toopenthe said valve.

A second exhaust port 40, located beneath the abovementioncd exhaustport 32, is provided so that combustion gases beneathpiston 17 mayescape through this additional port 40 when exhaust port 32 is coveredby piston 17, or when exhaust port 32 is located between the piston andthe top wall of the cylinder.

Gases in the combustion chamber 27, in addition to passing to theouteratmosphere through the valve 30 and exhaust ports 32 and 40, maypass to the outer atmosphere through a bore 37 formed in the rod 19,extending axially along the same'from the bottom end thereof, and havinga bottom open end "in communication with the combustion chamber, andthrough a pair of lateral bores 38 formed in the rod 19,'having outeropen ends, and comrnunicating with the upper end portion of the bore 37.Thus, whenever the bore 37 communicates with the combustion chamber andthe bores 33 are located above the top wall 26 of cylinder 1 so that thebore 38 communicate with the outer atmosphere, the bores 37 and 38 willprovide an additional passage from'the combustion chamber to the outeratmosphere.

From the foregoing description and the accompanying drawing the featuresand characteristics of the new arrangements for explosion-driven ramminghammers will be clearly apparent. However, it should remain understoodthat the arrangements described may be modified in practice as totheir'details of construction without exceeding the scope of the presentinvention.

Having now particularly described my invention what I claim as new anddesire to protect by Letters Patent is:

1. In a ramming'apparatus, in-combination, a cylinder having a top walland beingformed in a side wall portion with an exhaust port locateddistant from said top wall; a piston slidably mounted in said cylinderfor movement above and below said exhaust port andhaving a top faceforming a combustion chamber with said top wall; first spring meansoperatively connected to said piston for urging the same toward said topwall; exhaust valve means mounted on said piston to providecommunication between the interior parts of said cylinder located onopposite sides of said piston, said exhaust valve means including avalve member engaging said top face of said piston in the closedposition of said exhaust valve means and being spaced from saidtop faceof said piston and located in said combustion chamber in the openposition of said exhaust valve means; second spring means operativelyconnected to said valve member for urging the same to the open positionthereof; intake valve means communicating with said combustion chamberfor admitting a combustible mixture thereto during movement of saidpiston away from said top wall; and manually operable means for manuallymoving said piston away from said top wall of said cylinder to draw acombustible mixture into said combustion chamber'an'd for simultaneouslymanually moving said valve member to the closed position thereof,whereby, when the mixture in said combustion chamber is ignited, thepressure of the explosion will maintain said valve member in the closedposition thereof, and whereby, after said exhaust port is locatedbetween said piston and top wall, the pressure of the explosion will bereduced, said first spring means will move said piston toward said topwall, and second spring means will move said valve member to the openposition thereof to provide communication between said combustionchamber and exhaust port when said piston is located between saidexhaust port and top wall of said cylinder.

2. In a ramming apparatus as claimed in claim 1, said manually operablemeans comprising a rod extending slidably through said top wall andhaving a bottom free end portion located in said combustion chamber oversaid valve member to engage and move the latter against said top face ofsaid piston to close said exhaust valve means and simultaneously movesaid piston away from said top well against the action of said firstspring means.

3. Ina ramming apparatus as defined in claim 2, said bottom free endportion of said rod being formed with a substantially axial boreextending inwardly from the extremity of said bottom free end portion ofsaid rod, and said 'rod being formed with a lateral bore communicatingwith said axial bore and being spaced from the extremity of said bottomfree end portion of said rod so that when said lateral bore is locatedabove said top wall the interior of said combustion chamber communicateswith the outer atmosphere through said axial and lateral bores of saidpiston.

4. In a ramming apparatus as defined in claim 2, said manually operablemeans further including a substantially U-shaped member having oppositelegs located on opposite sides of said cylinder, having a substantiallycentral portion fixed to said rod adjacent the top end portion thereof,and a third spring means connected to said cylinder and U-shaped memberfor urging said substantially central portion thereof away from said topwall of said cylinder and away from said piston to urge said rod out ofsaid cylinder.

5. In a ramming apparatus as defined in claim 1, said cylinderbeingfor'med with atle'ast one additional exhaust port located moredistant from said top wall than said first-mentioned exhaust port sothat gases on the side of said piston opposite from said combustionchamber may escape through said additional exhaust port when saidfirst-mentioned exhaust port is coveredby said piston or is locatedbetween the latter and said top wall of said cylinder.

6. In a ramming apparatus as-defined in claim 1, a striker shaftlocatedin said cylinder on the side of said piston opposite from saidcombustion chamber to be engaged by said'piston.

7. In a ramming apparatus as defined in claim 6, said striker shaftbeing tubular and having a top open end, and said first spring meansbeing located within said striker shaft to extend through said top openend thereof for'moving said piston toward said top wall of saidcylinder.

References cited in the file of this patent UNITED STATES PATENTS1,858,707 Haage et al. May 17, 1932 2,053,720 Huck Sept. 8, 19362,072,224 Seidl Mar. 2, 1937 2,123,563 Cresien July 12, 1938 2,396,627Wohlmeyer Mar. 12, 1946 2,533,487 Maurer et al. Dec. 12, 1950 2,543,126Philippovic Feb. 27, 1951

